Ok, well, I picked one up yesterday just to find out.

When I compared the specs between the casio and my old panasonic ae900e, I suspected I'd be in for a bit of a letdown.
And that's exactly what happened.
First off, I will say a couple positive things about the casio.
1) it's BRIGHT. Did I mention how BRIGHT the dang thing is? I had to turn the brightness way down actually to keep the picture from saturating. Even in the middle of the day is a somewhat sunny room, the image was completely visible and watchable.
2) it's small, and white. If you were ceiling mounting it, it'd almost disappear into a normal white ceiling.
3) It'd got keystone correction, which seems to work pretty good.
4) if the lamp life really is 20000+ hours, that would truly be awesome.
But I won't be keeping it that long :'(
that's about all the pros, unfortunately.
Now the cons.
1) The Zoom is rotten, you simply can't zoom most TV source material properly. You'll end up with stuff above or below the picture, or you'll have the sides cut off. I couldn't figure any combination that worked smoothly. With the ae900u, get the picture to the right size what simply a matter of pressing the ASPECT button several times till it was right.
2) There's noticeable "screendoor"
3) The colors just aren't +right+. I tweaked on it for a good hour or more, and never was able to get things to look correct. Kind of close maybe, but not right.
4) The contrast ratio is just not good for home theater. The ae900u was 5500:1, which I thought was pretty good, maybe not fantastic, but OK. The casio is 1800:1 and it completely shows. Blacks aren't black. There's noticeable bleed through. Dark scenes are muddy, and just don't look good at all.
5) It's just not sharp. Even HD material through the HDMI port appears somewhat fuzzy. I'm suspecting the lower resolution.
6) It's got video in, standard computer VGA in and HDMI in, but no svideo or composite in. Not a huge downer, but worth pointing out.
7) It's got no lens shift, so getting it to project to your screen is a LOT of trial and error. Fortunately, in a normal HT environment, that should be too much of a downer.
Long story short, the xj-a140 (and it's brethren) would probably work out perfectly well as a REALLY portable movie station for rolling out on the deck and watching movies on a big sheet or on the side of your house. and It'd likely work nicely as a portable projector for business presentations.
But it's just not good enough yet for home theater.
And keep in mind that I am NOT a home theater snob by any stretch. A Runco would be great, but we're talking small to moderate budget here. And we're also talking about a household with exactly 1 (one) TV, which is the one in the family room that get's used every single time we watch any tv at all. So I knew going into the projector arena that we were going to be hitting it likely harder than most people putting in Home theaters would be hitting their projectors.
But, the casio will be going back to BestBuy today, and I'll start looking for something else.
Right now, I'm thinking either
1) another panasonic, either another ae-900u, or maybe an ax200u, AE2000u or AE4000u (though those things are 2000$, which is a tad steep for me).
2) An optoma hd20 (I've read some pretty good things about it) and the bulbs aren't too bad.
3) a Mitsubishi HC5500 (read good stuff on this too, plus I was always VERY happy with my Mitsu 32" tube tv, fantastic life out of that bad boy), but the bulbs on this seem to be pretty pricy.